BTV (Broadcast Television) is used to distribute television channels to subscribers using IP (Internet Protocol) multicasting. Each channel is assigned an IP multicast group address. Nodes in a group of nodes subscribe to IP multicast groups assigned to channels to be received by the group of nodes. IGMP (Internet Group Management Protocol) filters in the nodes are applied to customer ports to limit which channels are available to a given location or to a given subscriber. When a subscriber selects a particular TV channel, a request to receive that channel is sent from the subscriber's set top box to a network node responsible for that subscriber. If, for example, the subscriber has paid for a package that includes the selected channel, the IGMP filter will allow the selected channel to be transmitted from the node to the subscriber's set top box.
Presently, each node must be individually configured for all of the IP multicast group addresses and filters. The same set of IP multicast addresses must be entered many times. They must be entered on each node and again for each filter. This is time consuming and error-prone. It is done either directly on each node or using an element manager. An element manager is a software interface that provides a GUI (graphical user interface) for interacting with the node. Each node must still be configured individually.
For example, to set up TV channels, an operator must define the set of TV channels and associate them with multicast groups, such as Class D IP Addresses. An example of how this is done involves an operator typing in addresses as follows:
CBC→230.1.1.1;
CTV→230.1.1.2;
A&E→230.1.1.3;
TSN→230.1.1.4; and
DISC→230.1.1.5.
Next, the operator must configure the appropriate nodes to receive content on the multicast group addresses. This must be done individually for all nodes in a group of nodes, such as a ring of nodes. For the examplary channels given above, the following configuration steps must be performed for each node in the group:
add multicast group 230.1.1.1;
add multicast group 230.1.1.2;
add multicast group 230.1.1.3;
add multicast group 230.1.1.4; and
add multicast group 230.1.1.5.
For any logical packages of channels (Basic, Premium, etc), the operator must configure an IGMP filter on each node, individually. For example the operator may perform the following steps to set up Basic and Premium packages:
Set up for Basic:
Basic (CBC, CTV); assign filter ID 800;
IGMP filter 800 permit 230.1.1.1;
IGMP filter 800 permit 230.1.1.2;
IGMP filter 800 Deny All Others;
Set up for Premium:
Premium (A&E, DISC, TSN); assign the filter ID 801;
IGMP filter 801 permit 230.1.1.3;
IGMP filter 801 permit 230.1.1.4;
IGMP filter 801 permit 230.1.1.5;
IGMP filter 801 deny all others;
Set up for Basic and Premium:
Basic And Premium; assign the filter ID 802;
IGMP filter 802 permit 230.1.1.1;
IGMP filter 802 permit 230.1.1.2;
IGMP filter 802 permit 230.1.1.3;
IGMP filter 802 permit 230.1.1.4;
IGMP filter 802 permit 230.1.1.5;
IGMP filter 802 deny All Others.
When adding a new subscriber or modifying a subscriber, the operator must assign an IGMP filter for each customer at an appropriate node. For example if customer A wants Basic (where ID 800 is Basic), the operator must configure the appropriate node as follows:
use IGMP filter 800 on port 1/1/1.
If the customer wants customized TV channels (CBC, A&E), the operator must create a special IGMP filter and configure the node as follows:
IGMP filter 850 permit 230.1.1.1;
IGMP filter 850 permit 230.1.1.3;
IGMP filter 850 deny all others; and
Use IGMP filter 850 on port 1/1/1.
As can be seen from the above, configuring a group of nodes involves typing in multicast addresses many times, i.e. for each node to be configured. This is very susceptible to errors. Each node must be configured individually to receive the multicast addresses and filters must be individually created for each user port.